Nozzle intended for spinning artificial silk



Jan. 23, 1934. E. ORIOLI 1,944,293

NOZZLE INTENDED FOR SPINNING ARTIFICIAL SILK Filed March 27, 1928 avwemto'c Patented Jan. 23, 1934 UNITED STATES NOZZLE INTENDED FOR SPINNING ARTIFICIAL SILK Ernesto Orioli, Milan, Italy, assignor to Ruth- Aldo Company, Incorporated, New York, N. Y.

Application March 27, 1928, Serial No. 265,170, and in France January 9, 1928 1 Claim.

In spinning artificial silk it is known that the quality of the silk is closely connected with the nature, form and dimensions of the spinning nozzle and the manner in which it is made, no matter whether it is a question of dry-spinning collodion, in a gas, or of spinning with coagulation of the threads in a precipitating liquid.

The diversity of these factors explains the considerable number of types of spinning nozzles Which have been proposed, and also the relatively large number of patents and patent applications there are, in connection with these important pieces of apparatus, in the various countries.

The first improvement made: consisted in replacing the single-jet nozzle by a spinning nozzle with a plurality of orifices; but it was soon realized that the construction of such spinning nozzles presented unforeseen difiiculties which were not suspected at the outset.

For example, it has been found very difficult to ensure a uniform circulation of the precipitating liquid among the various single filaments in course of formation. It transpired that the exchanges of temperature were not always very regular, and that there existed such differences of temperature among the various orifices that a modification of the viscosity ensued, and consequently, irregularities in the size and the qualities of the single filaments.

It has also been found, in the particular case of dry spinning, that the distribution of the orifices over a plane surface presented serious inconveniences, such as greatly increasing the clog- 5 ging of the individual orifices, and also increasing the successive breakage of the filaments through the spreading of the collodio-n on the breakage of one of their number.

In order to obviate these various inconveniences, it has been proposed to provide the surface of the spinning nozzle with a series of radial channels, or concentric channels, with the object of producing a better circulation of the bath in the interior of the bundle of filaments in course of formation (German Patents No. 319,444 and With a similar object, it has been proposed to distribute the orifices over a conical surface (German Patent No. 403,735).

Finally, there has been proposed a. type of spinning nozzle designed to effect simultaneously the stretching (Streckspinnverfahren") of the filaments in course of formation (German Patent No. 395,524) and to obtain a better circulation of the surrounding fluid. In my opinion,

however, this device unfortunately fails to take into account the laws governing the issue of a liquid through an orifice, since it does not permit of a regular fiow of the solution to be spun to the spinning orifices.

I have found--and this forms the subject matter of the present inventionthat really surprising and advantageous results are obtained by disposing the spinning orifices, not on a plane surface, but in the centre of a series of cavities, in the form of caps, previously stamped out in the base of the nozzle, their convex faces being on the outside. This is particularly conducive to uniformity of the size of the single filaments and to regularity of spinning. It facilitates starting the spinning and also cleaning while spinning is in progress.

The accompanying drawing illustrates, merely by Way of example, a multiple-orifice spinning nozzle according to the invention, in sectional elevation (Fig. 1) and in plan (Fig. 2).

As illustrated, the spinning nozzle is composed of a stamped or pressed cup G, which may be of nickel, platinum, silver, or other material. In the base S of this cup are stamped or pressed a series of small hemispherical nipples T T T T T T T T T their convex faces being outside. In the bottom of these are provided the calibrated orifices O O O O O O 0", O 0 which determine the denier of the filament.

The spinning nozzle thus has a collection of distributing nipples for the silk-forming liquid.

Obviously, the diameter and number of the orifices, and the form and capacity of the caps or nipples are chosen according to the denier of the filament desired and the type of solution used.

With this very simple device I have obtained excellent circulation among the various single filaments While avoiding the development of superficial eddies-i Moreover, the transmission of heat from the coagulant gas or liquid and the issuing filament is more satisfactory than with other suggested devices.

The multiple-nipple spinning nozzle according to my invention also exhibits the advantage of remaining clean. In fact, in the event of one of the orifices becoming accidentally fouled, the

spinning solution remains adhering to the tip of 1 of each nipple is circular prevents any disturbance of the rate of discharge.

The advantages of the system of spinning according to the invention are decided and apparent, whatever the method of spinning adopted, whether it be by causing the spinning nozzle to operate in a gaseous fluid, such as air, nitrogen, or carbon dioxide, or in an aqueous or organic liquid.

This disposition of the orifices at the tips of nipples offers the further advantage of furnishing directly a jet of the spinning solution, even in the case of highly viscous liquids, whereas with a spinning nozzle displaying a plane surface and operating under the same conditions, the frequent result is the production of a drop which progressively increases in size and is very dimcult to transform, by continued wipings, into a filament-forming jet.

Should the formation of a drop accidentally occur with my nozzle as herein described, a mere touch with a piece of woollen cloth suffices to restore regular spinning at once.

A spinneret for spinning artificial silk comprising a body portion of relatively thin sheet metal having a fiat portion, a plurality of spaced partispherical nipples formed by deforming the metal to produce convex projections on the delivery side of the fiat portion and corresponding concave recesses on the opposite side, with the faces of the convex portions terminating in the plane of the plane of the fiat plate on the delivery side, and the faces of the concave recesses terminating in the plane of the flat plate on the opposite side, said nipples having central spinning orifices.

ERNESTO ORIOLI. 

